added levenshtein

Author: Arpita23r

levenshtein.R

@@ -0,0 +1,38 @@
+# Levenshtein Distance in R
+# Calculates minimum number of edits (insert, delete, replace)
+# to convert one string into another and prints the distance.
+
+levenshtein_distance <- function(s1, s2) {
+  n <- nchar(s1)
+  m <- nchar(s2)
+  
+  # Initialize DP matrix
+  dp <- matrix(0, nrow = n + 1, ncol = m + 1)
+  
+  for (i in 0:n) dp[i + 1, 1] <- i
+  for (j in 0:m) dp[1, j + 1] <- j
+  
+  # Fill DP table
+  for (i in 1:n) {
+    for (j in 1:m) {
+      if (substr(s1, i, i) == substr(s2, j, j)) {
+        dp[i + 1, j + 1] <- dp[i, j]
+      } else {
+        dp[i + 1, j + 1] <- min(
+          dp[i, j + 1] + 1,   # Deletion
+          dp[i + 1, j] + 1,   # Insertion
+          dp[i, j] + 1        # Substitution
+        )
+      }
+    }
+  }
+  
+  return(dp[n + 1, m + 1])
+}
+
+# Interactive input
+s1 <- tolower(readline("Enter first string: "))
+s2 <- tolower(readline("Enter second string: "))
+
+distance <- levenshtein_distance(s1, s2)
+cat("Levenshtein distance between '", s1, "' and '", s2, "' is:", distance, "\n")